Fire warning device



Sept- 10, 1957 R. G. BABSON 2,806,108

FIRE WARNING DEVICE] Filed Nov. 21, 1956 2 Sheets-Sheet 1 Fig /a Robrf6. Babson IN VENTOR.

BY MM FM Spt. 10, 1957 R. G. BABSON 2,806,108

FIRE WARNING DEVI E ODGI'I 6. 5005017 INVENTOR- FlRE WARNING DEVICERobert G. Babson, Pacific Palisades, Calif. Application November 21,1956, Serial No. 623,750

4 Claims. (Cl. 200-138) This invention relates to a fire detection andwarning device especially adapted for use in homes and other buildingswhich is adapted to provide an aural and visual warning as may bedesired of the presence of excessive heat in a predetermined location.

The primary object of the present invention resides in the provision ofa fire warning device of exceedingly simple construction which does notrequire any permanent wiring so as to be readily usable in any locationhaving a conventional outlet box or female connector into which theprongs of the devices can be inserted, and which may be widelydistributed in View of its low manufacturing cost.

A further object of the invention resides in the provision of a tirewarning device which is made in three suitable sections and in which thenoise making unit can be separated from the thermal switch unit toprovide remote detection where desired.

An additional object of the invention resides in the provision of a firewarning device capable of operating over a wide range of temperatures soas to give maximum protection in various climates and situations andwhich fire Warning device may be easily adapted for use in controllingthe operation of fans or the like when so desired.

Still further objects and features of this invention reside in theprovision of a fire warning device which can be hung close to theceiling or on the ceiling so as to be readily accessible by rising heatin a closed compartment or room, and which is unobtrusive in appearance.

These, together with the various ancillary objects and features of theinvention which will become apparent as the following descriptionproceeds, are attained by this fire warning device, preferredembodiments of which have been illustrated in the accompanying drawings,by way of example, wherein:

Figure 1 is a perspective view of the thermal switching element utilizedin the present invention;

Figure 2 is a bottom plan view of the thermal switching element shownwith the bottom cover removed therefrom;

Figure 3 is a transverse sectional view as taken along the plane of line3-3 of Figure 2;

Figure 4 is a perspective view of the cam controlling the position ofthe bimetallic element;

Figure 5 is a perspective view of the bimetallic element;

Figure 6 is a perspective view of the fixed contact with the permanentmagnet associated therewith;

Figure 7 is a perspective view of the aural warning element;

Figure 8 is a perspective view of the element looking at the undersidethereof;

Figure 9 is a perspective view of a stop action bimetallic switch whichcan be utilized in lieu of the switch shown in Figure 2;

Figure 10 is a perspective view of the extension member; and

Figure 11 is a side elevational view of a stacked assembly of devicesused in the invention.

With continuing reference to the accompanying drawaural warning nitedStates Patent Office 2,806,108 Patented Sept. 10, 1957 ings wherein likereference numerals designate similar parts throughout the various views,reference numeral 10 generally designates a casing having suitableopenings as at 12 on each side thereof through which hot air can pass.The casing 10 is also provided with an arcuate slot 14 therein and asocket 16 having openings as at 18 for reception of a prong connector asprovided in the casing 10. Mounted in the casing 10 are a pair of prongsas indicated at 20 and 22. Prong 22 is connected directly to one side ofthe female socket 16. Prong 20 is connected to the bimetallic element 38and connects to the other half of female socket 16 only when contacts 44and 46 are closed. An insulative base or block 24 is provided andpivotally mounted as at 26 on the base 24 is a cam member 28 having acam surface 30 and also having an indicator as at 32 which extends upthrough the slot 14 and cooperates with suitable indicia 34 inscribed onthe casing 10 or printed thereon for indicating the setting at which itis desired for the switch arrangement to operate.

By means of fasteners 36, a bimetallic element 38 is secured within thecasing 10, the fasteners being threadedly secured in an extension 40 ofthe socket assembly 16. A threaded adjusting screw 42 is threadedlyengaged within the bimetallic element adapted to engage the cam surface30 of the cam member 28 so as to adjust the position initially of thebimetallic element 38 dependent of course upon the setting of theindicator 32.

Mounted on the bimetallic element 38 is a stainless steel contact 44. Ofcourse, the contact may be made of other suitable ferrous or magneticmaterial but stainless steel is preferred in View of the fact that it isless likely to pit or corrode. This stainless steel contact 44cooperates with a fixed contact 46 in order to complete an electricalcircuit from the prongs 20 and 22 to the socket l6. Mounted about thestainless steel fixed contact 46 which is carried by a contact plate 48is a permanent magnet 50. This permanent magnet 50 will function toensure a snap action of the switching arrangement so as to prevent anyarcing across the contacts 44 and 46. When the two contacts 44 and 46approach each other within or so, the magnet 50 will pull the contact 44rapidly into contact with the fixed contact 46 so as to prevent arcingwhile closing the circuit. As the temperature lowers several degrees,the magnet is overcome by the movement of the bimetallic strip 38 andthe contacts open rapidly.

In lieu of the snap action arrangement of the bimetallic element. 38 andthe magnetized set of contacts, a bimetallic element as shown in Figure9 and indicated at 60 may be utilized which incorporates a spring 62therein functioning to cause the contact 64 to engage contact 66 bymeans of snap action and to be disengaged therefrom dependent upon, ofcourse, the temperature to which the device has been set to operate.

It is noted that the arm 52 of the cam member 28 is offset from theother portions thereof so as to assure that the arm 52 will notinterfere with the contacts 44 and 46 and the operation thereof.Further, this cam member is preferably formed of a suitable insulatingmaterial so as to prevent any shock hazard.

The casing it, is designed to have :a housing snapped thereon; it beingnoted that the housing 80 is of substantially the same dimensions as thecasing 10 leaving room only for operation of the indicator 32. This canbe seen best in Figure 11. The housing 80 includes a prong connector 82the right prong of which is connected directly with one half of a femaleconnector 84 and also to a conductor 81 connected to a horn 94 or othersuitable alarm. The left prong of connector 82 is connected to abimetallic element 83 of flasher unit 88 by conductor 86. The other halfof female socket 84 is connected to the fixed portion 85 of the flasherunit which is connected by conductor 87 to the horn 94 or other suitableaudible alarm. Hence, when the contacts 46 and 44 are closed, the horn94 will intermittently sound. A lamp may be inserted in the femaleconnector 84 so that a flashing light signal can be obtained.

In order to achieve remote connection for the device, there is provideda remote connection arrangement including member 100 in the form of acase having a female socket connector 102 associated therewith adaptedto receive the prongs and 22 therein. An extension cord 104 including aprong connector 196 is connected to the female socket connector 102 sothat the case 100 may be situated remote from a source of electricalpower. It is noted that the case is of a Wedge shape and is ofsubstantially the same dimensions as the casing 10 so that the casingit} may be stacked thereon and the entire device may be readily hung ona wall by means of a picture nail or the like in any convenientposition. The casing 10, the housing 8i) and the case 100 are made ofsubstantially the same size so that all three units will appear to beone when they are used together. There may be a small loop at the top ofthe case 100 so that it can be hung in a desired location on a picturehanger or nail.

The device may be used to awaken parents or baby sitters if there aresmall children in a distant room or may be used to give fire alarmprotection to business establishments such as a store or the like.

When a radio is used as the alarm device it is plugged into femalesocket 16 in case 10 as this will provide a continuous current whencontacts 44 and 46 are closed. It is also within the concept of thisinvention to build this device into a radio set to give fire warningprotection by turning the set on in case of temperature rise above theset temperature.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. A temperature responsive warning device comprising a casing, a pairof prongs mounted in said casing for connection to a source ofelectrical power, a socket arrangement mounted in said casing forreception of an electrical connector, a bimetallic element in saidcasing connected to one of said prongs and said socket and having amovable contact thereon, a fixed contact in said casing connected toanother of said prongs and said socket, cam means engaging saidbimetallic element for determining the position of said bimetallicelement, and a spring associated with said bimetallic element to snapsaid movable contact into engagement and away from said fixed contact, ahousing having a prong connector and a female connector affixed thereto,said prong connector being received in said socket, a bimetallic flasherunit connected to said prong connector, and an audible alarm connectedto said'fiasher unit.

2. A temperature responsive warning device comprising a casing, a pairof prongs mounted in said casing for connection to a source ofelectrical power, a socket arrangement mounted in said casing forreception of an electrical connector, a bimetallic element in saidcasing connected to one of said prongs and said socket and having amovable contact thereon, a fixed contact in said casing connected toanother of said prongs and said socket, cam means engaging saidbimetallic element for determining the position of said bimetallicelement, and a spring associated with said bimetallic element to snapsaid movable contact into engagement and away from said fixed contact, ahousing having a prong connector and a female connector aflixed thereto,said prong connector being received in said socket, a bimetallic flasherunit connected to said prong connector, and an audible alarm connectedto said flasher unit, said housing and said casing having substantiallythe same dimensions and configuration, a case of substantially the samedimensions as said housing and said casing, a female socket connectorafiixed in said case receiving said pair of prongs, and an extensioncord connected to said female socket connector for connection to asource of electrical power.

3. A temperature responsive warning device comprising a casing, a pairof prongs mounted in said casing for connection to a source ofelectrical power, a socket arrangement mounted in said casing forreception of an electrical connector, a bimetallic element in saidcasing connected to one of said prongs and said socket and hav ing amovable contact thereon, a fixed contact in said casing connected toanother of said prongs and said socket, cam means engaging saidbimetallic element for determining the position of said bimetallicelement, and a magnet about said fixed contact, said movable contactbeing of a magnetic material, a housing having a prong connector and afemale connector alfixed thereto, said prong connector being received ina said socket, a bimetallic flasher unit connected to said prongconnector, and an audible alarm connected to said fiasher unit, saidhousing and said casing having substantially the same dimensions andconfiguration, a case of substantially the same dimensions as saidhousing and said casing, a female socket connector aifixed in said casereceiving said pair of prongs, and an extension cord connected to saidfemale socket connector for connection to a source of electrical power.

4. A temperature responsive warning device comprising a casing, a pairof prongs mounted in said casing for connection to a source ofelectrical power, a socket arrangement mounted in said casing forreception of an electrical connector, a bimetallic element in saidcasing connected to one of said prongs and said socket and having amovable contact thereon, a fixed contact in said casing connected toanother of said prongs and said socket, cam means engaging saidbimetallic element for determining the position of said bimetallicelement and a spring associated with said bimetallic element to snapsaid movable contact into engagement and away from said fixed contact, ahousing having a prong connector and a female connector af'fixedthereto, said prong connector being received in said socket, abimetallic flasher unit connected to said prong connector, and anaudible alarm connected .to said flasher unit, said housing and saidcasing having substantially the same dimensions and configuration, acase of substantially the same dimensions as said housing and saidcasing, a female socket connector affixed in said case receiving saidpair of prongs, and an extension cord connected to said female socketconnector for connection to a source of electrical power.

References Cited in the file of this patent UNITED STATES PATENTS Leins'Jan. 17, 1956

